China will begin the trial on July 28 of a Korean-American missionary arrested last year over a non-profit school he ran near the sensitive border with North Korea, his lawyer said, in a case that sparked outcry from international Christian groups.

A sprawling crackdown had forced hundreds of Christian missionaries out of China, most by having their visas refused, sources told Reuters last August.

Supporters of Peter Hahn, the missionary, had said he was being targeted because of his Christian faith and because of the small vocational school he ran.

Authorities have dropped three of the four charges against Hahn, 74, probably for lack of evidence, his lawyer, Zhang Peihong, told Reuters, leaving only the least serious charge of counterfeiting receipts.

"I wouldn't call my attitude optimistic," Zhang said by telephone. "After all Peter has only done good works, so he shouldn't face any punishment. I do hope the court will act impartially."

Hahn could receive a maximum of two years in prison, Zhang said, but he expected authorities would simply deport him back to the United States instead.

His school in the border town of Tumen had been shut down after an investigation last year that lasted months, he said.

Hahn, who was formally arrested in December after months under house arrest, will be tried in Yanbian prefecture, near the North Korean border in northeast China, Zhang added.

Yanbian law enforcement authorities could not be reached for comment. A spokesman for the U.S. embassy in Beijing said he could not immediately comment on the development.

Hahn's health has improved as the weather has warmed, but his family has not been able to meet him, Zhang said. Hahn has diabetes and has suffered strokes, his wife has said.

Last year, a Canadian Christian couple who worked with North Korean refugees and ran a coffee shop in Dandong on the Chinese border were accused of espionage by the Chinese government.